Talk:Introductory PLC Programming

Hi folks

Warm Wishes for your contribution to enhance "Introductory PLC Programming" wikibook. I request the Contributors to avoid Manufacturer specific descriptions. If we decide to add manufacturer specific info., we need to identify contributors working on different vendor products.

Thanks VJ

I'm sure i'm in the wrong place but didn't have time to parse all your rules. There is an inconsistency in Intro PLC Prog in the Basic Instructions section:

Positive Logic (most PLCs follow this convention) True = logic 1 = input energized. False = logic 0 = input NOT energized. Negative Logicﺑ True = logic 0 = input NOT energized False = logic 1 = input energized. Normally Open (XIC) - eXamine If Closed. This instruction is true (logic 1) when the hardware input (or internal relay equivalent) is energized. Normally Closed (XIO) - eXamine If Open. This instruction is true (logic 1) when the hardware input (or internal relay equivalent) is NOT energized.

The last line under (XIO) above is not consistent with either the Positive Logic definition nor the Negative Logic definition just above it (i.e. ...true (logic 1)...is NOT energized).

The XIO instruction can be considered as a "NOT" gate.Yacieng (discuss • contribs) 06:57, 15 October 2020 (UTC)